Brain scans may one day spot autism

Brain imaging may someday help doctors detect autism by showing the electrically conductive microscopic fibres that compose our white matter, according to a recent US study.

Researchers found that people between the ages of 8 and 26 showed differences in the ways their brains responded to linguistic, emotional, and social stimuli.

The researchers showed that the right side of the brains is more organised than the left side in autists, in the areas where language and social skills are processed.

Usually, people's linguistic and social processing happens in the left side of the brain.

The type of brain imaging used, magnetic resonance imaging (MRI), measures the circuitry of people's brains, and the researchers noticed the most differences in the superior temporal gyrus and temporal stem, two important regions which are both located in the brain's temporal lobe.

For the recent study, the researchers used diffusion tensor imaging, a type of MRI scan that tends to offer more information about the actual structure of the brain rather than which parts of it 'light up'.

For the purposes of the study, the researchers recruited 30 male subjects who had been diagnosed with autism, as well as 30 male subjects who had not.

Based on the assessments they later made about the difference between autistic brains and normal brains, the researchers could diagnose autism with a 94% success rate.

There is currently no biological test for autism, and the process by which doctors tell if children are autistic currently requires much involvement from doctors.

However, the MRI-based method may someday replace such lengthy diagnoses, which involve regular behavioural, linguistic, and social checkups.

Nicholas Lange, director of the Neurostatistics Laboratory at McLean Hospital and an associate professor of psychiatry at Harvard Medical School, said that his team's study pinpointed disruptions in the circuitry of brain regions long known to influence linguistic expression, as well as the social and emotional functioning of adults.

MRI-based methods for detecting autism would not only be quicker and less costly than current methods.

Lange said that the brain scanning techniques studied by his research team may also help the development of new treatments for autism.

Stewart Mostofsky, medical director at the Kennedy Krieger Institute's Center for Autism and Related Disorders in Baltimore, Maryland, said that advancing the MRI-based approach would require studying more children, as well as a broader range of children with autism.

He said the technique would also require studying other development disorders, particularly other developmental language disorders.

Doctors also do not know enough about the development of the brain during childhood to accurately predict when children should be checked for signs of autism.

While the cells in the brain are almost completely undifferentiated at birth, neurons begin to connect rapidly, and the brain assumes a surprising amount of structure by the first 18 to 24 months of life.

Lange said that the brains of people tended to process language in the left side, where the structure of white matter looked very organised and fibrous, while the opposite was true of autists, whose superior temporal gyrus tended to be more organised on the right side of the brain than on the left.